Marijuana is the most commonly used illicit drug in the United States and internationally and nearly one-third of current marijuana users in the U.S. suffer from a marijuana use disorder (MUD). Thus, identification of individual difference factors related to marijuana use among current users has important public health implications. One such individual difference factor is social anxiety. Social anxiety disorder (SAD), a disorder characterized by fear of scrutiny in social situations, is thought to serve as a risk and maintaining for marijuana use. The present proposal is designed to meet the objectives of the Exploratory/Developmental grants (R21) program to encourage innovative, exploratory and developmental research whose findings have promise to advance health-related research regarding the prevention and treatment of MUD. Specifically, the proposed R21 outlines a novel approach to understanding vulnerability to marijuana use by examining the physiological, cognitive, and emotional antecedents of marijuana use among individuals with and without an identified psychological vulnerability to marijuana-related problems (those with SAD) using a multi-method approach in a series of two studies. In Study 1, antecedents of marijuana craving will be examined under controlled laboratory conditions using a social anxiety manipulation paradigm. If social anxiety is a risk factor for using marijuana to manage anxious reactions, it follows that elevations in state social anxiety should elicit marijuana craving, particularly among those with SAD. We will test this hypothesis by inducing state social anxiety and examining whether increases in self-reported anxiety and physiological arousal predict increases in marijuana craving. Further, participants will provide reasons for marijuana use while experiencing anxiety- induced craving. In Study 2, ecological momentary assessment (EMA) will be used to examine the naturalistic antecedents of marijuana use and assess (1) the extent to which social anxiety-provoking situations serve as a risk factor for marijuana use and (2) the affective, situational, and cognitive antecedents of marijuana among those with and without SAD. It is believed that the use of multiple methodologies will provide convergent and complementary data regarding affective, situational, and cognitive variables related to marijuana use. For instance, examination of the relations between state social anxiety and marijuana in the laboratory will allow us to test whether physiological arousal predicts marijuana craving whereas using EMA allows for the collection of data regarding actual marijuana use in real-life situations. The proposed studies will provide important information regarding proximal factors that maintain marijuana use as well as shed light on the understudied relationship between SAD and MUD. Such data have direct, translational implications for the prevention and treatment of marijuana use and MUD. PUBLIC HEALTH RELEVANCE: Marijuana is the most commonly used illicit drug in the United States and internationally, with nearly one-third of users experiencing marijuana-related problems significant enough to warrant a diagnosis of marijuana use disorder (MUD). People with social anxiety disorder experience particular difficulty managing marijuana use. The present project uses state-of-the-art scientific methodology to study proximal factors related to marijuana use among those with and with SAD.